William frank browne



(No Model.)

W.- F. BRoWNB. PNEUMATIG PUMP. No. 570,372. Patented Oct. 27, 1896.

WITNESSES:

UNITED STATES PATENT FFCE..

`TILLIAM FRANK BROXVNE, OF NEV YORK, N. Y.

PN EUNIATIC PUM P.

SPECIFICATION forming part of Letters Patent No. 570,372, dated October 27, 1896. Application led August 15, 1896. Serial No. 602,867. (No model.)

BROWNE, a citizen of the UnitedStates, and' a resident of New York city, in the county and State of New York, have invented certain new and useful Improvements in Pneumatic Pumps, of which the following is a specification.

This invention relates to a pneumatic pump in which the piston or plunger is forced back into the raised or retracted position by means .0f a suitable spring.

The object of the invention is to provide a4 pneumatic pump which is simple in construction and which is effective and durable in use.

The matter constituting my invention will be defined in the claims.

I will now describe the details of construction and operation of my improved pump by reference to the accompanying drawings, in which- Figure l represents a vertical central section of the pump. Fig. 2 represents an elevation of the pump barrel or cylinder, the piston or plunger being depressed and inclosed within the same. Fig. 3 represents a side elevation of a slightly-modified form of pump with parts broken away.

The preferred form of my pump is illustrated in Figs. Vl and 2. The cylindrical barrel A is preferably made by drawing or spinningfrom a suitable piece of metal, so as to form it without seam -or joint, and is provided at the top with a concave flange Z) and at the bottom with a boss a, having a screwthreaded opening for attachment of an escape-pipe. The piston or plunger B, Fig. l, is preferably made hollow with a cylindrical lower end and a conical upper end, or, more correctly, with the upper end in the form of the frustum of a cone with a central upper opening and with the upper edge turned over to form an outwardly-projecting flange d, which is preferably concave at the under side, as shown. The plunger B is hollow and has a bottom plate o", provided near its outer edge with suitable openings a. A disk b3 of some pliable material, such as leather, and having a turned-over edge h4, is secured be- 5o tween the bottom plate b and a metallic disk The disk b5 is made of sufficient diameter to permitthe pliable edge b4 of the packingdisk b3 to yield and admit air between it and the wall of the cylinder into the chamber below. It will be evident that air is admitted through the openings a during the upward stroke of the plunger B. On the downward stroke of the plunger the pliable edge h4 will be forced against the wall of the cylinder, making therewith a tight joint, so that the air will be forced out of the chamber through the perforated boss a. The upper part of the piston, which projects above the cylindrical barrel, is made conical for the purpose of permitting the spiral spring C to telescope and all of its turns to lie, one Within the other, in the same horizontal plane inside of the iiange b, thus permitting the piston to be depressed and entirely inclosed within the pump-barrel. The lower end of the spring C is supported on the iiange b of the barrel and the upper end thereof bears against the under side of the flange d of the plunger. By reason of the conical form of the upper end of plunger B the pressure of the foot will be exerted thereon centrally and therefore overcome the tendency of the plunger to tilt and bind, as it otherwise might if the sides were straight and the pressure was applied to one side thereof.

The piston or plunger B maybe made with parallel walls throughout its length, as shown in Fig. 3, and with this construction the supportin g-iian ge b for spring C is preferably secured a little below the top of the cylinder A. In this construction the spring C will be coiled around the periphery of cylinderAand, when the plunger B is depressed, will lie in the space between the top of cylinder A and the flange b.

The spiral or coiled spring C serves the purpose of forcing the plunger back or into a raised position after it has been depressed by the operator. By attaching a pipe to the screw-threaded boss a air'may be conducted to any holder or place of use, such as a pneu- 'matic bicycle-tire.

This pump is very light and simple in construction and well adapted to be set upon the floor or ground and operated by the pressure of the foot, applied to the top of plunger B, for forcing air into bicycle-tires or other place of use.r

IOO

Having described my invention, what I claim, and desire to secure byLetters Patent, is-

1. In a pneumatic pump, the cylinder or barrel, having a circumferential flange and the hollow piston or plunger having a conical upper end and an outwardly-turned iiange at or near its top, in combination with an outer spiral spring interposed between and bearing on said flanges and the coils thereof lying adjacent to said conical portion of the plunger, substantially as and for the purpose described.

2. In a pneumatic pump, the cylinder or barrel, having a circumferential flange at, or near, its top and the hollow piston or plunger having a conical upper end, provided with an 

